Means for spreading cut tobacco



June 1931- F. H. B. STELZER MEANS FOR SPREADING CUT TOBACCO 1, 1929 2 Sheets-Sheet 1 Filed Aug.

June 1931' F. H. a. STELZER MEANS FOR SPREADING CUT TOBACCO Filed Aug.

1, 1929 2 Sheets-Sheet 2 Patented June 9, 1931 UNITED S. PATENT OFFICEFT,

FRANZ HEINRICH BENNO STELZER, OF DRESDEN, GERMANY, ASSI GNOR TO THE UNIVERSE-LLB CIGARETTENMASCHINEN-FABRIK, J. C. MULLER & 'CO., OF

DRESDEN, GERMANY MEANS FOR SPREADING GUT TOBACCO Application filed August 1, 1929, Serial No. 382,612, and in Germany July 5, .1928.

In order to take care of the tobacco in tobacco spreaders and protect the fibres before the tearing operation it has been proposed to lead past the tobacco hopper a travelling 5 sieve band or the like subjected to suction action on which the tobacco fibres of the supply hopper settle so that a fleece of tobacco forms on the sieve and on the further movement of the sieve the suction action is inter- 10 rupted so that a uniform stream of tobacco is delivered from the sieve in the form of aband on to a conveyor. Y

In order to separate the tobacco fleece with certainty from the sieve band I have already provided at the point where the suction action is interrupted a nozzle which forces compressed air through the openings in the sieve band and blows the fleece of tobacco off the said band.

In order to simplify the construction of such apparatus in accordance with the present invention the chamber subjected to suction action at that side which is closed by the moving sieve band or the like and at the point where the fleece is delivered by the said band or the like is gradually contracted so that finally by the frictional resistance thereby produced the air stream is atfected in a manner favourably influencing the separation of the tobacco fleece from. the sieve band. It is thus possible to dispense with the compressed air nozzle without rendering uncertain the complete removal of the tobacco fleece from the sieve band.

In the accompanying drawings which form part of this specification and in which similar reference characters denote corre sponding parts;

Figs. 1, 2 and 3 are respectively vertical sections of each of three embodiments.

In the construction illustrated in Fig. 1 the moving sieve band 5 is formed as a rotary drum the tobacco being drawn by the drum from the supply hopper 1. The tobacco fibres are straightened by the jet 14 in the form of a slot by means of compressed air. The brushing roller 16 regulates the thickness of the fleece which moves with the drum and remains under the suction action of the drum until it reaches the forward edge of the cover 12 in which. there is'no vacuum. This cover or cap is so shaped as to form between the part 50 of its wall and the wall of thedrum a chamber 51 running to a point.

'As the result the suction action on this face of the wall of thedrum bounding this chamber gradually diminishes until it fallsto zero at the edge 17. The tobacco-has nowan opportunity to separate gradually from the sifting drum "until at the edge 17 :it is comair. The brushing roller 16 brings the fleece to the desired thickness. .In this embodiment also the suction chamber (orsuction b02139) runs to a pointed chamber 51. The suction action gradually diminishes as the said band moves towards this chamber 51 and consequently the tobacco fleece gradually falls from the sieve band and passes'to the feed band 19 and from thereto the grooved conveyor 23. I I

The problem of gradually reducing the suction action of the suction chamber '39 in order to permit of dispensing with the use of a compressed air jet can also be solved by the gradual separation of the suction chamber at the side at which it is closed bythe moving sieve band 5 or the like from such sieve band towards the point where thefleece is delivered from the sieve band or the like so as to leave a space 52 through which additional air may be drawn into the chamber '39 so that the flow of air under suction is affected in a manner which facilitates the release of the tobaccofleece from the sieve band. I 7

One form of this solution is illustrated in Fig. 3. The above description of Fig. '2 applies to this figure. Byfth'e passage of air through the gap 52 between the suction chamber 29 and the sieve band 5 the suction action exerted by the suction chamber through the sieve band on the fleece is gradually weakened. In consequence the tobacco fleece gradually separates from the sieve band passes on to the feed band 19 and thence to the grooved conveyor 23.

I claim: 1. Means for spreading out tobacco comprising a moving sieve band for carrying a tobacco fleece,a suction chamber closed by said band and means for gradually reducing the suction action exerted on said sieve band towards one end whereby the fleece may be delivered from the sieve band.

2. Means for spreading out tobacco comprising a moving perforated band for carrying a tobacco fleece, a suction chamber closed by said band at one side and receding from v the perforated band at another point whereby to form a gap between the suction chamber and said band forthe supply of additional air and whereby to release the fleece from said perforated band. a v

3. Means for spreading out tobacco com prising a moving perforated member carrying a tobacco fleece, a suction chamber having an open end, the latter being closed by said perforated member and means for gradually reducing the suction action exerted on said perforated member toward the delivery end of the latter whereby the fleece may be delivered therefrom. g

4. Means for spreading out tobacco comprising a moving perforated band for carrying a tobacco fleece, means for regulating the thickness of said fleece, a suction chamber closed by said band at one side and receding from the said band at another point whereby to form a gap between the suction chamber and said band for the supply of additional air to release said fleece from said band and means for conveying said released fleece away from said band; a

5. Means for spreading cut tobacco comprising a moving perforated band for carrying a tobacco fleece, a suction chamber closed by said band, means for regulating the thickness of said fleece, means for reducing the suction action exerted on said perforated band towards the delivery point of the latter whereby the fleece may be delivered from said band and means for removing said de livered fleece.

6. Means for spreading out tobacco comprising a moving perforated member for I carrying a tobacco fleece,'means for directing suction actlon through a portion of sa1d member and means near the dellvery point of the latter for reducing said suction action gradually whereby said fleece may be removed.

In testimony whereof I aflix my signature.

FRANZ HEINRICH BENNO STELZER. 

